Porphyromonas gingivalis polypeptides and nucleotides

ABSTRACT

The present invention relates to isolated  Porphyromonas gingivalis  polypeptides and nucleotides. The polypeptides include an amino acid sequence selected from the group consisting of: SEQ. ID. NO. 110; SEQ. ID. NO. 111; SEQ. ID. NO. 112; SEQ. ID. NO. 113; SEQ ID NO: 120; SEQ. ID. NO. 123; SEQ. ID. NO. 124; SEQ. ID. NO. 125; SEQ. ID. NO. 130; SEQ. ID. NO. 131; SEQ. ID. NO. 132; SEQ. ID. NO. 133; SEQ. ID. NO. 135; SEQ. ID. NO. 136; SEQ. ID. NO. 137; SEQ. ID. NO. 138; SEQ. ID. NO. 143; SEQ. ID. NO. 144; SEQ. ID. NO. 145; SEQ. ID. NO. 146; SEQ. ID. NO. 147; SEQ. ID. NO. 148; and amino acid sequences at least 95% identical thereto.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of application Ser. No.11/589,261, filed Oct. 30, 2006, which is a continuation of applicationSer. No. 09/581,286, filed Jun. 28, 2000, which is a 317 ofPCT/AU98/01023 filed Dec. 10, 1998, the entire contents of each of theseapplications is incorporated herein by reference. In particular, theentire contents of application Ser. No. 11/589,261, pending, isincorporated herein by reference, including specifically the sequence IDnumbers: SEQ. ID. NO. 1 to SEQ ID NO: 721.

FIELD OF THE INVENTION

The present invention relates to Porphyromonas gingivalis nucleotidesequences, P. gingivalis polypeptides and probes for detection of P.gingivalis. The P. gingivalis polypeptides and nucleotides can be usedin compositions for use in raising an immune response in a subjectagainst P. gingivalis and treating or preventing or reducing theseverity of the condition known as periodontitis.

BACKGROUND OF THE INVENTION

Periodontal diseases are bacterial-associated inflammatory diseases ofthe supporting tissues of the teeth and range from the relatively mildform of gingivitis, the non-specific, reversible inflammation ofgingival tissue to the more aggressive forms of periodontitis which arecharacterised by the destruction of the tooth's supporting structures.Periodontitis is associated with a subgingival infection of a consortiumof specific Gram-negative bacteria that leads to the destruction of theperiodontium and is a major public health problem. One bacterium thathas attracted considerable interest is P. gingivalis as the recovery ofthis microorganism from adult periodontitis lesions can be up to 50% ofthe subgingival anaerobically cultivable flora, whereas P. gingivalis israrely recovered, and then in low numbers, from healthy sites. Aproportional increase in the level of P. gingivalis in subgingivalplaque has been associated with an increased severity of periodontitisand eradication of the microorganism from the cultivable subgingivalmicrobial population is accompanied by resolution of the disease. Theprogression of periodontitis lesions in non-human primates has beendemonstrated with the subgingival implantation of P. gingivalis. Thesefindings in both animals and humans suggest a major role for P.gingivalis in the development of adult periodontitis.

P. gingivalis is a black-pigmented, anaerobic, asaccharolytic,proteolytic Gram-negative rod that obtains energy from the metabolism ofspecific amino acids. The microorganism has an absolute growthrequirement for iron, preferentially in the form of haeme or its Fe(III)oxidation product haemin and when grown under conditions of excesshaemin is highly virulent in experimental animals. A number of virulencefactors have been implicated in the pathogenicity of P. gingivalisincluding the capsule, adhesins, cytotoxins and extracellular hydrolyticenzymes.

In order to develop an efficacious and safe vaccine to prevent,eliminate or reduce P. gingivalis colonisation it is necessary toidentify and produce antigens that are involved in virulence that haveutility as immunogens possibly through the generation of specificantibodies. Whilst it is possible to attempt to isolate antigensdirectly from cultures of P. gingivalis this is often difficult. Forexample as mentioned above, P. gingivalis is a strict anaerobe and canbe difficult to isolate and grow. It is also known that, for a number oforganisms, when cultured in vitro that many virulence genes are downregulated and the encoded proteins are no longer expressed. Ifconventional chemistry techniques were applied to purify vaccinecandidates potentially important (protective) molecules may not beidentified. With DNA sequencing, as the gene is present (but nottranscribed) even when the organism is grown in vitro it can beidentified, cloned and produced as a recombinant DNA protein. Similarly,a protective antigen or therapeutic target may be transiently expressedby the organism in vitro or produced in low levels making theidentification of these molecules extremely difficult by conventionalmethods.

With serological identification of therapeutic targets one is limited tothose responses which are detectable using standard methods such asWestern Blotting or ELISA. The limitation here is the both the level ofresponse that is generated by the animal or human and determiningwhether this response is protective, damaging or irrelevant. No suchlimitation is present with a sequencing approach to the identificationof potential therapeutic or prophylactic targets.

It is also well known that P. gingivalis produces a range of broadlyactive proteases (University of Melbourne International PatentApplication No PCT/AU 96/00673, U.S. Pat. Nos. 5,475,097 and 5,523,390),which make the identification of intact proteins difficult because oftheir degradation by these proteases.

SUMMARY OF THE INVENTION

The present inventors have attempted to isolate P. gingivalis nucleotidesequences which can be used for recombinant production of P. gingivalispolypeptides and to develop nucleotide probes specific for P.gingivalis. The DNA sequences listed below have been selected from alarge number of P. gingivalis sequences according to their indicativepotential as vaccine candidates. This intuitive step involved comparisonof the deduced protein sequence from the P. gingivalis DNA sequences tothe known protein sequence databases. Some of the characteristics usedto select useful vaccine candidates include; the expected cellularlocation, such as outer membrane proteins or secreted proteins,particular functional activities of similar proteins such as those withan enzymatic or proteolytic activity, proteins involved in essentialmetabolic pathways that when inactivated or blocked may be deleteriousor lethal to the organism, proteins that might be expected to play arole in the pathogenesis of the organism eg. red cell lysis, cellagglutination or cell receptors and proteins which are paralogues toproteins with proven vaccine efficacy.

In a first aspect the present invention consists of an isolatedantigenic Porphyromonas gingivalis polypeptide or an antigenic fragmentthereof, the polypeptide comprising an amino acid sequence selected fromthe group consisting of: SEQ. ID. NO. 110; SEQ. ID. NO. 111; SEQ. ID.NO. 112; SEQ. ID. NO. 113; SEQ ID NO: 120; SEQ. ID. NO. 123; SEQ. ID.NO. 124; SEQ. ID. NO. 125; SEQ. ID. NO. 130; SEQ. ID. NO. 131; SEQ. ID.NO. 132; SEQ. ID. NO. 133; SEQ. ID. NO. 135; SEQ. ID. NO. 136; SEQ. ID.NO. 137; SEQ. ID. NO. 138; SEQ. ID. NO. 143; SEQ. ID. NO. 144; SEQ. ID.NO. 145; SEQ. ID. NO. 146; SEQ. ID. NO. 147; and SEQ. ID. NO. 148;

or amino acid sequences at least 95% identical to an amino acid sequenceselected from the group consisting of: SEQ. ID. NO. 110; SEQ. ID. NO.111; SEQ. ID. NO. 112; SEQ. ID. NO. 113; SEQ ID NO: 120; SEQ. ID. NO.123; SEQ. ID. NO. 124; SEQ. ID. NO. 125; SEQ. ID. NO. 130; SEQ. ID. NO.131; SEQ. ID. NO. 132; SEQ. ID. NO. 133; SEQ. ID. NO. 135; SEQ. ID. NO.136; SEQ. ID. NO. 137; SEQ. ID. NO. 138; SEQ. ID. NO. 143; SEQ. ID. NO.144; SEQ. ID. NO. 145; SEQ. ID. NO. 146; SEQ. ID. NO. 147; and SEQ. ID.NO. 148;

or an amino acid sequence of at least 40 amino acids having a contiguoussequence of at least 40 amino acids identical to a contiguous amino acidsequence selected from the group consisting of: SEQ. ID. NO. 110; SEQ.ID. NO. 111; SEQ. ID. NO. 112; SEQ. ID. NO. 113; SEQ ID NO: 120; SEQ.ID. NO. 123; SEQ. ID. NO. 124; SEQ. ID. NO. 125; SEQ. ID. NO. 130; SEQ.ID. NO. 131; SEQ. ID. NO. 132; SEQ. ID. NO. 133; SEQ. ID. NO. 135; SEQ.ID. NO. 136; SEQ. ID. NO. 137; SEQ. ID. NO. 138; SEQ. ID. NO. 143; SEQ.ID. NO. 144; SEQ. ID. NO. 145; SEQ. ID. NO. 146; SEQ. ID. NO. 147; andSEQ. ID. NO. 148.

As used herein % identity for polypeptides is to be calculated using thealignment algorithm of Needleman and Munsch (9) using a standard proteinscoring matrix (Blosum 50).

In a preferred embodiment the present invention provides a polypeptideor fragment thereof, the polypeptide comprising an amino acid sequenceselected from the group consisting of: SEQ. ID. NO. 110; SEQ. ID. NO.111; SEQ. ID. NO. 112; SEQ. ID. NO. 113; SEQ ID NO: 120; SEQ. ID. NO.123; SEQ. ID. NO. 124; SEQ. ID. NO. 125; SEQ. ID. NO. 130; SEQ. ID. NO.131; SEQ. ID. NO. 132; SEQ. ID. NO. 133; SEQ. ID. NO. 135; SEQ. ID. NO.136; SEQ. ID. NO. 137; SEQ. ID. NO, 138; SEQ. ID. NO, 143; SEQ. ID. NO.144; SEQ. ID. NO. 145; SEQ. ID. NO. 146; SEQ. ID. NO. 147; and SEQ. ID.NO. 148.

In a second aspect the present invention consists in an isolated DNAmolecule, the DNA molecule comprising a nucleotide sequence whichencodes the polypeptide of the first aspect of the present invention ora sequence which hybridises thereto under stringent conditions.

It is preferred that the isolated DNA molecule comprises a nucleotidesequence selected from the group consisting of SEQ ID NO: 36 to SEQ IDNO: 39; SEQ ID NO: 46; SEQ ID NO: 49 to SEQ ID NO: 51; SEQ ID NO: 56 toSEQ ID NO: 59; SEQ ID NO: 61 to SEQ ID NO:64; SEQ ID NO: 69 to SEQ IDNO: 74; SEQ ID NO: 3 to SEQ ID NO: 5; SEQ ID NO: 11; SEQ ID NO: 14 toSEQ ID NO: 16; SEQ ID NO: 21; SEQ ID NO: 22; SEQ ID NO: 24 to SEQ ID NO:26; SEQ ID NO: 28 to SEQ ID NO: 33.

In a third aspect the present invention consists in a recombinantexpression vector comprising the DNA molecule of the second aspect ofthe present invention operably linked to a transcription regulatoryelement.

The present invention also provides a cell comprising this recombinantexpression vector.

In a further aspect the present invention consists in a method forproducing a P. gingivalis polypeptide comprising culturing the cellunder conditions that permit expression of the polypeptide.

In yet a further aspect the present invention provides a composition foruse in raising an immune response directed against P. gingivalis in asubject, the composition comprising an effective amount of at least onepolypeptide of the first aspect of the present invention, or at leastone DNA molecule of the second aspect of the present invention, or both,and a pharmaceutically acceptable carrier. It is preferred that thepharmaceutically acceptable carrier is an adjuvant. In other aspects thepresent invention provides methods of treating P. gingivalis infectionin subject comprising the administration of the composition to thesubject such that treatment of P. gingivalis infection occurs. Thetreatment may be prophylactic or therapeutic.

In yet another aspect the present invention provides an antibody raisedagainst a polypeptide of the first aspect the invention. The antibodymay be polyclonal or monoclonal. The present invention also providescompositions including these antibodies. It is preferred that thesecompositions are adapted for oral use and may be, for example,dentrifices, mouthwashes, etc.

In a still further aspect the present invention provides a nucleotideprobe comprising at least 18 nucleotides and having a contiguoussequence of at least 18 nucleotides identical to a contiguous nucleotidesequence selected from the group consisting of SEQ ID NO: 3 to SEQ IDNO: 5; SEQ ID NO: 11; SEQ ID NO: 14 to SEQ ID NO: 16; SEQ ID NO: 21; SEQID NO: 22; SEQ ID NO: 24 to SEQ ID NO: 26; SEQ ID NO: 28 to SEQ ID NO:33; and sequences complementary thereto. It is preferred that the probefurther comprises a detectable label.

The present invention also provides a method for detecting the presenceof P. gingivalis nucleic acid in a sample comprising:

-   -   (a) contacting a sample with the nucleotide probe under        conditions in which a hybrid can form between the probe and a P.        gingivalis nucleic acid in the sample; and    -   (b) detecting the hybrid formed in step (a), wherein detection        of a hybrid indicates the presence of a P. gingivalis nucleic        acid in the sample.

DETAILED DESCRIPTION Definitions

A purified or isolated polypeptide or a substantially pure preparationof a polypeptide are used interchangeably herein and, as used herein,mean a polypeptide that has been separated from other proteins, lipids,and nucleic acids with which it naturally occurs. Preferably, thepolypeptide is also separated from substances, e.g., antibodies or gelmatrix, e.g., polyacrylamide, which are used to purify it. Preferably,the polypeptide constitutes at least 10, 20, 50 70, 80 or 95% dry weightof the purified preparation. Preferably, the preparation contains:sufficient polypeptide to allow protein sequencing; at least 1, 10, or100 mg of the polypeptide.

A purified preparation of cells refers to, in the case of plant oranimal cells, an in vitro preparation of cells and not an entire intactplant or animal. In the case of cultured cells or microbial cells, itconsists of a preparation of at least 10% and more preferably 50% of thesubject cells.

A purified or isolated or a substantially pure nucleic acid, e.g., asubstantially pure DNA, (are terms used interchangeably herein) is anucleic acid which is one or both of the following: not immediatelycontiguous with both of the coding sequences with which it isimmediately contiguous (i.e., one at the 5′ end and one at the 3′ end)in the naturally occurring genome of the organism from which the nucleicacid is derived; or which is substantially free of a nucleic acid withwhich it occurs in the organism from which the nucleic acid is derived.The term includes, for example, a recombinant DNA which is incorporatedinto a vector, e.g., into an autonomously replicating plasmid or virus,or into the genomic DNA of a prokaryote or eukaryote, or which exists asa separate molecule (e.g., a cDNA or a genomic DNA fragment produced byPCR or restriction endonuclease treatment) independent of other DNAsequences. Substantially pure DNA also includes a recombinant DNA whichis part of a hybrid gene encoding additional P. gingivalis DNA sequence.

A “contig” as used herein is a nucleic acid representing a continuousstretch of genomic sequence of an organism.

An “open reading frame”, also referred to herein as ORF, is a region ofnucleic acid which encodes a polypeptide. This region may represent aportion of a coding sequence or a total sequence and can be determinedfrom a stop to stop codon or from a start to stop codon.

As used herein, a “coding sequence” is a nucleic acid which istranscribed into messenger RNA and/or translated into a polypeptide whenplaced under the control of appropriate regulatory sequences. Theboundaries of the coding sequence are determined by a translation startcodon at the five prime terminus and a translation stop code at thethree prime terminus. A coding sequence can include but is not limitedto messenger RNA synthetic DNA, and recombinant nucleic acid sequences.

A “complement” of a nucleic acid as used herein refers to ananti-parallel or antisense sequence that participates in Watson-Crickbase-pairing with the original sequence.

A “gene product” is a protein or structural RNA which is specificallyencoded by a gene.

As used herein, the term “probe” refers to a nucleic acid, peptide orother chemical entity which specifically binds to a molecule ofinterest. Probes are often associated with or capable of associatingwith a label. A label is a chemical moiety capable of detection. Typicallabels comprise dyes, radioisotopes, luminescent and chemiluminescentmoieties, fluorophores, enzymes, precipitating agents, amplificationsequences, and the like. Similarly, a nucleic acid, peptide or otherchemical entity which specifically binds to a molecule of interest andimmobilizes such molecule is referred herein as a “capture ligand”.Capture ligands are typically associated with or capable of associatingwith a support such as nitro-cellulose, glass, nylon membranes, beads,particles and the like. The specificity of hybridization is dependent onconditions such as the base pair composition of the nucleotides, and thetemperature and salt concentration of the reaction. These conditions arereadily discernible to one of ordinary skill in the art using routineexperimentation.

Homologous refers to the sequence similarity or sequence identitybetween two polypeptides or between two nucleic acid molecules. When aposition in both of the two compared sequences is occupied by the samebase or amino acid monomer subunit, e.g., if a position in each of twoDNA molecules is occupied by adenine, then the molecules are homologousat that position. The percent of homology between two sequences is afunction of the number of matching or homologous positions shared by thetwo sequences divided by the number of positions compared×100.

The terms peptides, proteins, and polypeptides are used interchangeablyherein.

An “immunogenic component” as used herein is a moiety, such as an P.gingivalis polypeptide, analog or fragment thereof, that is capable ofeliciting a humoral and/or cellular immune response in a host animal.

An “antigenic component” as used herein is a moiety, such as P.gingivalis polypeptide, analog or fragment thereof, that is capable ofbinding to a specific antibody with sufficiently high affinity to form adetectable antigen-antibody complex.

As used herein, the term “cell-specific promoter” means a DNA sequencethat serves as a promoter, i.e., regulates expression of a selected DNAsequence operably linked to the promoter, and which effects expressionof the selected DNA sequence in specific cells of a tissue. The termalso covers so-called “leaky” promoters, which regulate expression of aselected DNA primarily in one tissue, but cause expression in othertissues as well.

As used herein, the term “control sequence” refers to a nucleic acidhaving a base sequence which is recognized by the host organism toeffect the expression of encoded sequences to which they are ligated.The nature of such control sequences differs depending upon the hostorganism; in prokaryotes, such control sequences generally include apromoter, ribosomal binding site, terminators, and in some casesoperators; in eukaryotes, generally such control sequences includepromoters, terminators and in some instances, enhancers. The termcontrol sequence is intended to include at a minimum, all componentswhose presence is necessary for expression, and may also includeadditional components whose presence is advantageous, for example,leader sequences.

As used herein, the term “operably linked” refers to sequences joined orligated to function in their intended manner. For example, a controlsequence is operably linked to coding sequence by ligation in such a waythat expression of the coding sequence is achieved under conditionscompatible with the control sequence and host cell.

A “sample” as used herein refers to a biological sample, such as, forexample, tissue or fluid isolated from an individual (including withoutlimitation plasma. serum, cerebrospinal fluid, lymph, tears, saliva andtissue sections) or from in vitro cell culture constituents, as well assamples from the environment.

The practice of the invention will employ, unless otherwise indicated,conventional techniques of chemistry, molecular biology, microbiology,recombinant DNA, and immunology well known to those skilled in the art.Such techniques are described and explained throughout the literature insources such as, J. Perbal, A Practical Guide to Molecular Cloning, JohnWiley and Sons (1984), J. Sambrook et al., Molecular Cloning: ALaboratory Manual, Cold Spring Harbour Laboratory Press (1989), T. A.Brown (editor), Essential Molecular Biology: A Practical Approach,Volumes 1 and 2, IRL Press (1991), D. M. Glover and B. D. Hames(editors), DNA Cloning: A Practical Approach, Volumes 1-4, IRL Press(1995 and 1996), and F. M. Ausubel et al. (Editors), Current Protocolsin Molecular Biology, Greene Pub. Associates and Wiley-Interscience(1988, including all updates until present). The disclosure of thesetexts are incorporated herein by reference.

Pharmaceutically Acceptable Carriers

The antibodies, polypeptides and DNA of the present invention can beincluded in compositions which include a carrier or diluent. Thesecompositions include pharmaceutical compositions where the carrier ordiluent will be pharmaceutically acceptable. Pharmaceutically acceptablecarriers or diluents include those used in compositions suitable fororal, rectal, nasal, topical (including buccal and sublingual), vaginal,parenteral (including subcutaneous, intramuscular, intravenous,intradermal, intrathecal and epidural) administration. They arenon-toxic to recipients at the dosages and concentrations employed.Representative examples of pharmaceutically acceptable carriers ordiluents include, but are not limited to; water, isotonic solutionswhich are preferably buffered at a physiological pH (such asphosphate-buffered saline or Tris-buffered saline) and can also containone or more of, mannitol, lactose, trehalose, dextrose, glycerol,ethanol or polypeptides (such as human serum albumin). The compositionsmay conveniently be presented in unit dosage form and may be prepared byany of the methods well known in the art of pharmacy.

As will be well understood by those skilled in the art alterations maybe made to the amino acid sequences set out in the Sequence Listings.These alterations may be deletions, insertions, or substitutions ofamino acid residues. The altered polypeptides can be either naturallyoccurring (that is to say, purified or isolated from a natural source)or synthetic (for example, by performing site-directed metagenesis onthe encoding DNA). It is intended that such altered polypeptides whichhave at least 85%, preferably at least 95% identity with the sequencesset out in the Sequence Listing are within the scope of the presentinvention. Antibodies raised against these altered polypeptides willalso bind to the polypeptides having one of the sequences set out in theSequence Listings. The level of % identity is to be calculated as setout above.

Protein sequences are homologous if they are related by divergence froma common ancestor. Consequently, a species homologue of the protein willbe the equivalent protein which occurs naturally in another species.Within any one species a homologue may exist as numerous allelicvariants, and these will be considered homologues of the protein.Allelic variants and species homologues can be obtained by followingstandard techniques known to those skilled in the art.

An allelic variant will be a variant that is naturally occurring withinan individual organism.

Mutants, Variants and Homology—Nucleic Acids

Mutant polynucleotides will possess one or more mutations which aredeletions, insertions, or substitutions of nucleotide residues. Mutantscan be either naturally occurring (that is to say, isolated from anatural source) or synthetic (for example, by performing site-directedmetagenesis on the DNA). It is thus apparent that polynucleotides of theinvention can be either naturally occurring or recombinant (that is tosay prepared using recombinant DNA techniques).

An allelic variant will be a variant that is naturally occurring withinan individual organism.

Nucleotide sequences are homologous if they are related by divergencefrom a common ancestor. Consequently, a species homologue of thepolynucleotide will be the equivalent polynucleotide which occursnaturally in another species. Within any one species a homologue mayexist as numerous allelic variants, and these will be consideredhomologues of the polynucleotide. Allelic variants and specieshomologues can be obtained by following standard techniques known tothose skilled in the art.

Antibody Production

Antibodies, either polyclonal or monoclonal, which are specific for apolypeptide of the present invention can be produced by a person skilledin the art using standard techniques such as, but not limited to, thosedescribed by Harlow et al. Antibodies: A Laboratory Manual, Cold SpringsHarbor Laboratory Press (1988), and D. Catty (editor), Antibodies: APractical Approach, IRL Press (1988).

Various procedures known in the art may be used for the production ofpolyclonal antibodies to epitopes of a protein. For the production ofpolyclonal antibodies, a number of host animals are acceptable for thegeneration of antibodies by immunization with one or more injections ofa polypeptide preparation, including but not limited to rabbits, mice,rats, etc. Various adjuvants may be used to increase the immunologicalresponse in the host animal, depending on the host species, includingbut not limited to Freund's (complete and incomplete), mineral gels suchas aluminium hydroxide, surface active substances such as lysolecithin,pluronic polyols, polyanions, oil emulsions, keyhole lympet hemocyanins,dinitrophenol, and potentially useful human adjuvants such as BCG(bacille Calmette-Guerin) and Corynebacterium parvum.

A monoclonal antibody to an epitope of a protein may be prepared byusing any technique which provides for the production of antibodymolecules by continuous cell lines in culture. These include but are notlimited to the hybridoma technique originally described by Kohler andMilstein (1975, Nature 256, 493-497), and the more recent human B-cellhybridoma technique (Kesber et al. 1983, Immunology Today 4:72) andEBV-hybridoma technique (Cole et al. 1985, Monoclonal Antibodies andCancer Therapy, Alan R. Liss, Inc. pp. 77-96). In addition, techniquesdeveloped for the production of “chimeric antibodies” by splicing thegenes from antibody molecule of appropriate antigen specificity togetherwith genes from a human antibody molecule of appropriate biologicalactivity may be used (Morrison et al. 1984, Proc. Natl. Acad. Sci.,81:6851-6855; Neuberger et al. 1984 Nature 312:604-608; Takeda et al.1985 Nature 31:452-454). Alternatively, techniques described for theproduction of single chain antibodies (U.S. Pat. No. 4,946,778) can beadapted to produce 4-specific single chain antibodies.

Recombinant human or humanized versions of monoclonal antibodies are apreferred embodiment for human therapeutic applications. Humanizedantibodies may be prepared according to procedures in the literature(e.g. Jones et al. 1986, Nature 321:522-25; Reichman et al. 1988 Nature332:323-27; Verhoeyen et al. 1988, Science 239:1534-36). The recentlydescribed “gene conversion metagenesis” strategy for the production ofhumanized monoclonal antibody may also be employed in the production ofhumanized antibodies (Carter et al. 1992 Proc. Natl. Acad. Sci. U.S.A.89:4285-89). Alternatively, techniques for generating the recombinantphase library of random combinations of heavy and light regions may beused to prepare recombinant antibodies (e.g. Huse et al. 1989 Science246:1275-81).

Antibody fragments which contain the idiotype of the molecule such as FuF(ab1) and F(ab2) may be generated by known techniques. For example,such fragments include but are not limited to: the F(ab) E2 fragmentwhich can be produced by pepsin digestion of the intact antibodymolecule; the Fab′ fragments which can be generated by reducing thedisulfide bridges of the F(ab′)2 fragment, and the two Fab fragmentswhich can be generated by treating the antibody molecule with papain anda reducing agent. Alternatively, Fab expression libraries may beconstructed (Huse et al. 1989, Science 246:1275-1281) to allow rapid andeasy identification of monoclonal Fab fragment with the desiredspecificity to a protein.

Adjuvants

“Adjuvant” means a composition comprised of one or more substances thatenhances the immunogenicity and efficacy of a vaccine composition.Non-limiting examples of suitable adjuvants include squalane andsqualene (or other oils of animal origin); block copolymers; detergentssuch as Tween®-80; Quil® A, mineral oils such as Drakeol or Marcol,vegetable oils such as peanut oil; Corynebacterium-derived adjuvantssuch as Corynebacterium parvum; Propionibacterium-derived adjuvants suchas Propionibacterium acne; Mycobacterium bovis (Bacillus Calmetic andGuerinn or BCG); interleukins such as interleukin 2 and interleukin-12;monokines such as interleukin 1; tumour necrosis factor; interferonssuch as gamma interferon; combinations such as saponin-aluminiumhydroxide or Quil-A aluminium hydroxide; liposomes; ISCOM adjuvant;mycobacterial cell wall extract; synthetic glycopeptides such as muramyldipeptides or other derivatives; Avridine; Lipid A; dextran sulfate;DEAE-Dextran or DHAE-Dextran with aluminium phosphate;carboxypolymethylene such as Carbopol EMA; acrylic copolymer emulsionssuch as Neocryl A640 (e.g. U.S. Pat. No. 5,047,238); vaccinia or animalposvirus proteins; sub-viral particle adjuvants such as cholera toxin,or mixtures thereof.

As used herein, stringent conditions are those that (1) employ low ionicstrength and high temperature for washing, for example, 0.015 MNaCl/0.0015 M sodium citrate/0.1% NaDodSO4 at 50° C.; (2) employ duringhybridisation a denaturing agent such as formamide, for example, 50%(vol/vol) formamide with 0.1% bovine serum albumin, 0.1% Ficoll, 0.1%polyvinylpyrrolidone, 50 mM sodium phosphate buffer at pH 6.5 with 750mM NaCl, 75 mM sodium citrate at 42° C.; or (3) employ 50% formamide,5×SSC (0.75 M NaCl, 0.075 M sodium citrate), 50 mM sodium phosphate (pH6.8), 0.1% sodium pyrophosphate, 5×Denhardt's solution, sonicated salmonsperm DNA (50 μg/ml), 0.1% SDS and 10% dextran sulfate at 42° C. in0.2×SSC and 0.1% SDS

As will be understood the present invention includes within its scopeDNA vaccination. Further information regarding DNA vaccination may befound in Donnelly et al, Journal of Immunological Methods 176 (1994)145-152, the disclosure of which is incorporated herein by reference.

Throughout this specification the word “comprise”, or variations such as“comprises” or “comprising”, will be understood to imply the inclusionof a stated element or integer or group of elements or integers but notthe exclusion of any other element or integer, or group of elements orintegers.

Preparation of the P. gingivalis Library for Sequencing.

To determine the DNA sequence of P. gingivalis genomic DNA was isolatedfrom P. gingivalis strain W50 (ATCC 53978) essentially by the methoddescribed by Mamur J. (J. Mol. Biol. 3, 208-218, 1961). Cloning of DNAfragments was performed essentially as described by Fleischmann et al.,(Science; 269, 496-512, 1995)(2). Briefly, purified genomic DNA from P.gingivalis was nebulized to fragment the DNA and was treated with Bal31nuclease to create blunt ends then run twice through preparative 1%agarose gels. DNA fragments of 1.6-2.0 kb were excised from the gel andthe DNA recovered. This DNA was then ligated to the vector pUC18 (SmaIdigested and dephosphorylated; Pharmacia) and electrophoresed through a1% preparative agarose gel. The fragment comprising linear vector plusone insert was excised, purified and this process repeated to reduce anyvector without insert contamination. The recovered vector plus insertDNA was blunt-ended with T4 DNA polymerase, then a final ligation toproduce circular DNA was performed. Aliquots of Epicurian ColiElectroporation-Competent Cells (Stratagene) were transformed with theligated DNA and plated out on SOB agar antibiotic diffusion platescontaining X-gal and incubated at 37° C. overnight. Colonies withinserts appeared white and those without inserts (vector alone) appearedblue. Plates were stored at 4° C. until the white clones were picked andexpanded for the extraction of plasmid DNA for sequencing.

DNA Sequencing

Plasmid DNA was prepared by picking bacterial colonies into 1.5 ml ofLB, TB or SOB broth supplemented with 50-100 ug/ml Ampicillin in 96 deepwell plates. Plasmid DNA was isolated using the QIAprep Spin or QIAprep96 Turbo miniprep kits (QIAGEN GmbH, Germany). DNA was eluted into a 96well gridded array and stored at −20 C.

Sequencing reactions were performed using ABI PRISM Dye Terminator andABI PRISM BIGDye Terminator Cycle Sequencing Ready Reaction kits withAmpliTaq DNA polymerase FS (PE Applied Biosystems, Foster City, Calif.)using the M13 Universal forward and reverse sequencing primers. Sequencereactions were conducted on either a Perkin-Elmer GeneAmp 9700 (PEApplied Biosystems) or Hybaid PCR Express (Hybaid, UK) thermal cyclers.Sequencing reactions were analysed on ABI PRISM 377 DNA sequencers (PEApplied Biosystems).

The sequences obtained are set out below. The relationship between thesesequences is set out in Table 1. The initiation codon was calculatedusing a combination of sequence homology alignment (FASTA), signalsequence prediction (PSORT, SignalP) or ORF prediction (GeneMark).

TABLE 1 Reference table indicating the relationships of each sequence IDto the selected proteins. DNA sequence Amino acid of sequence of DNAProtein complete complete sequence of Amino acid name ORF ORF proteinsequence of protein PG1 1 75 34 108 PG10 2 76 35 109 PG100 3 77 36 110PG102 4 78 37, 38 111, 112 PG104 5 79 39 113 PG11 6 80 40 114 PG12 7 8141 115 PG13 8 82 42 116 PG14 9 83 43 117 PG2 10 84 44, 45 118, 119 PG2111 85 46 120 PG22 12 86 47 121 PG24 13 87 48 122 PG25 14 88 49 123 PG2715 89 50 124 PG28 16 90 51 125 PG29 17 91 52 126 PG3 18 92 53 127 PG4 1993 54 128 PG5 20 94 55 129 PG54 21 95 56 130 PG57 22 96 57, 58, 59 131,132, 133 PG6 23 97 60 134 PG68 24 98 61, 62 135, 136 PG75 25 99 63 137PG76 26 100 64 138 PG8 27 101 65, 66, 67, 68 139, 140, 141, 142 PG91 28102 69 143 PG94 29 103 70 144 PG96 30 104 71 145 PG97 31 105 72 146 PG9832 106 73 147 PG99 33 107 74 148

DNA Sequence Analysis

DNA files in FASTA format were converted to GCG format files andimported into a database. The DNA files were translated into amino acidfiles using the program Flip obtained from ANGIS (Australian GenomicInformation Service, University of Sydney, Australia). A series ofbioinformatic analyses were performed on the proteins in order to selectpotential vaccine candidates. The programs used were FASTA homologysearching (1), PSORT (2,3), SignalP (4), TopPred (5), and GeneMark (6).The proteins and their bioinformatic results were stored in the customwritten database for search and retrieval of proteins with the desiredcharacteristics

The FASTA homology results for these proteins were then examined for anyalignment with a protein suggesting surface location or vaccineefficacy. All proteins were searched for homology against anon-redundant bacterial protein database compiled by ANGIS using theFASTA algorithm. The settings used for the FASTA searches were Ktup=2,gap creation penalty=−12, gap extension penalty=−2, width for derivingalignment in opt=16 and the Blosum 50 scoring matrix. Individual FASTAsearch results were examined for significant homology by statisticalprobability and amino acid alignments. The results are set out in Table2.

Protein files were then trimmed to the first, second, third, fourth andfifth methionine residues using a protein trimming program (ANGIS). Thetrimmed proteins were then subjected to PSORT analysis for the detectionof signal sequences and the prediction of cell location. Proteinsexhibiting a PSORT probability of outer membrane >0.8 were considered toindicate surface localisation. A second signal sequence detectionprogram SignalP was also performed and, in certain instances, thisprogram detected signals not identified with PSORT. All proteinsidentified by other methods were also analysed by PSORT and SignalP.Previously, the C-terminal amino acid of bacterial outer membraneproteins has been shown to be important for the assembly of the proteinon the outer membrane (7). A typical structure definition for outermembrane proteins has been determined as the presence of a signalsequence at the N-terminus and a tyrosine or phenylalanine at theC-terminus. A number of the selected proteins exhibit thischaracteristic structure. The program TopPred was used to determine thepresence and number of membrane spanning domains (MSDs) and the presenceof such sequences indicates a preference to be attached to membranessuch as the outer membrane. The results of PSORT, SignalP and TopPredanalyses with the C-terminal amino acids of the selected proteins areset out in Table 3.

The 70 amino acids from the C-terminus of a number of P. gingivalisouter membrane proteins share 50-100% protein sequence identity. Theseproteins included RGP1, RGP2, KGP, HagA, HagC, HagD, prtH and prtT. Thisconserved motif may be involved in the attachment or sorting of proteinsto the outer membrane. The protein data set was searched using FASTAhomology as described above and a number of novel proteins wereidentified which demonstrate similar motifs at their C-termini. Theresults are listed in Table 4

The TonBIII box is a 30 amino acid motif present within TonB outermembrane receptors in a wide variety of bacteria. The TonBIII box of P.gingivalis (8) was used to search the protein data set for homology byFASTA as described above. Those proteins demonstrating significanthomology are listed in Table 5.

TABLE 2 FASTA protein homology results of complete ORFs against anon-redundant protein database. Genbank Length of Protein accessionLength of P. gingivalis FASTA homology results name Homology descriptionnumber homolog protein Identity % Overlap E value PG1 48 kD outermembrane protein, Actinobacillus U24492  449aa  451aa 32  454aa 1.40E−42pleuropneumoniae PG2 Outer membrane protein (susC), Bacteroides L493381038aa 1017aa, 28 1099aa 4.60E−32 thetaiotaomicron 1014aa PG3 Outermembrane porin F adhesin, Pseudomonas U19743  317aa  223aa 35  187aa1.10E−10 fluorescens PG4 Outer membrane protein A, Escherichiafergusonii M63352  243aa  672aa 48  88aa 4.10E−10 PG5 Adhesin protein(AdcA), Streptococcus pneumoniae Z71552  423aa  315aa 25  279aa 9.40E−15PG6 Hemolysin A (phyA), Prevotella melaninogenica U27587  332aa  324aa60  306aa 3.00E−74 PG8 Heme uptake protein A, Bacteriodes fragilisX97122  431aa  598aa, 79  417aa 6.70E−121  550aa,  458aa,  426aa PG10Macrophage infectivity potentiator (MIP), Legionella U92214  234aa 195aa 50  201aa 4.70E−31 oakridgensis. PG11 Haemagglutinin (phg),Prevotella intermedia AF017417  309aa  313aa 44  309aa 3.60E−44 PG12Outer membrane lipoprotein, Haemophilus influenzae M68502  274aa  271aa36  254aa 9.60E−27 PG13 Ferric receptor (cfrA), Campylobacter coliU80812  696aa  757aa 24  625aa 1.20E−18 PG14 36 kD antigen, Helicobacterpylori U86610  329aa  331aa 37  326aa 1.10E−35 PG22 Alpha-hemolysingene, Aeromonas hydrophila L36462  85aa  106aa 57  67aa 2.60E−14 PG24Putative hemolysin, Streptococcus mutans AF051356  445aa  417aa 29 432aa 1.80E−29 PG25 Cysteine protease, Porphyromonas gingivalis U546911723aa  293aa 42  142aa 1.10E−12 PG27 TonB linked adhesin, Porphyromonasgingivalis Y07618 1097aa  312aa 45  360aa 3.20E−41 PG28 Cysteineprotease/hemagglutinin, Porphyromonas S75942  886aa  843aa 35  838aa7.00E−90 gingivalis PG54 Protease I, Achromobacter lyticus J5128  653aa 940aa 24  695aa 1.50E−22 PG57 Cysteine protease, Porphyromonasgingivalis U68468 1358aa  924aa, 31  742aa 1.40E−23 922aa, 921aa PG75Class 3 outer membrane porin (porB), Neisseria U07191  332aa  391aa 23 239aa 4.60E−01 meningitidis PG91 Neuraminidase (nanH), Bacteroidesfragilis D28493  544aa  540aa 24  251aa 1.60E+00 PG94 Arginylendopeptidase, Porphyromonas gingivalis D26470  991aa 1157aa 24  328aa7.60E−08 PG21 Surface antigen gene, Methanosarcina mazei X84710 7 83aa 821aa 37  331aa 6.20E−33

TABLE 3 Results of PSORT, SignalP and TopPred analysis of the proteins.The signal present column indicates the presence of a signal sequencedetected with either PSORT or SignalP. The terms in parenthesesindicates the type of signal sequence as determined by PSORT. The celllocation & probability values are generated by PSORT and represent theprobability of the protein being in the cell compartments outer membrane(OM), inner membrane (IM), periplasmic space (PC) or cytoplasm (C). Thenumber of transmembrane domains (TMDs) was determined by TopPred anddoes not include uncleavable signal sequences. Protein SignalP PSORTC-terminal Number Protein seqID Protein Methionine in cleavage cleavageCell Location & probability Amino of name number Length Signal PresentORF site site OM IM PS C Acid TMD's PG1 386 451aa Y 1 24 34 0 0 0 0.22 N0 PG2 424 1017aa  Y 1 20 20 0.94 0 0.33 0 F 3 PG2 425 1014aa  Y 2 17 170.94 0 0.29 0 F 3 PG3 434 223aa Y (lipoprotein) 1 — 18 0.79 0.76 0 0 K 3PG4 447 672aa Y (lipoprotein) 1 22 22 0.79 0.7 0 0 R 0 PG5 458 315aa Y 140 35 0 0.25 0 0 R 0 PG6 475 324aa N 1 — — 0 0 0 0.2 S 1 PG8 498 598aa N1 — — 0 0 0 0.22 N 0 PG8 499 550aa N 2 — — 0 0 0 0.25 N 0 PG8 500 458aaN 3 — — 0 0 0 0.34 N 0 PG8 501 426aa N 4 — — 0 0 0 0.24 N 0 PG10 387195aa N 1 — — 0 0 0 0.11 K 0 PG11 400 313aa Y 1 22 26 0.24 0 0.93 0 R 1PG12 411 271aa Y (lipoprotein) 3 27 29 0.79 0.7 0 0 R 0 PG13 419 757aa Y1 23 25 0.94 0 0.29 0 N 0 PG14 420 331aa Y (uncleavable) 1 35 26 0 0.580 0 K 1 PG21 426 821aa Y 2 24 27 0.34 0 0.37 0 G 1 PG22 427 106aa Y(uncleavable) 1 41 41 0 0.29 0 0 P 0 PG24 429 417aa Y 1 19 19 0 0.44 0 0N 3 PG25 430 293aa Y 1 27 28 0.2 0 0.62 0 R 0 PG27 431 312aa N 1 — — 0 00 0.28 Q 1 PG28 432 843aa Y 1 21 21 0.93 0 0.24 0 H 1 PG29 433 290aa Y 118 16 0.28 0 0.94 0 K 1 PG54 463 940aa Y 1 27 20 0.86 0 0.25 0 Q 5 PG57467 925aa Y 1 28 24 0.53 0 0.2 0 P 3 PG57 468 922aa Y 2 25 21 0.53 0 0.20 P 3 PG57 469 921aa Y 3 24 20 0.53 0 0.2 0 P 3 PG68 484 1226aa  Y 1 2525 0.91 0 0.31 0 Y 0 PG68 485 1225aa  Y 2 24 24 0.91 0 0.31 0 Y 0 PG75493 391aa Y 1 26 26 0.94 0 0.3 0 H 1 PG76 494 446aa Y 1 21 22 0.94 00.32 0 V 3 PG91 520 540aa Y 1 25 25 0.85 0 0.30 0 E 0 PG94 523 1157aa  Y1 23 28 0.8 0 0.25 0 Q 5 PG96 525 563aa Y 1 23 23 0.40 0 0.33 0 K 0 PG97526 437aa Y 1 23 23 0.32 0 0.65 0 Q 0 PG98 527 318aa Y (lipoprotein) 119 19 0.79 0.7 0 0 L 1 PG99 528 461aa Y (uncleavable) 1 22 20 0 0 0.3 0R 0 PG100 388 279aa Y 1 20 18 0.26 0 0.54 0 I 0 PG102 389 562aa Y 1 2929 0.19 0 0.4 0 S 3 PG102 390 558aa Y 2 25 25 0.26 0 0.46 0 S 3 PG104391 391aa Y 1 17 17 0.62 0 0.22 R 0

TABLE 4 Percentage identity and percentage similarity of variousproteins with the 70 amino acids from the C-terminal of the P.gingivalis arginine protease 1 (RGP1), arginine protease 2 (RGP2), andthe cysteine protease/hemagglutinin (prtT). Protein Percent identityPercent similarity name RGP1 RGP2 prtT RGP1 RGP2 prtT PG21 17 29 21 4057 49 PG25 43 41 9 64 73 14 PG27 41 33 7 73 74 11 PG28 21 26 34 49 57 74PG54 19 13 16 40 43 33 PG57 11 14 19 20 24 34 PG91 31 21 39 57 53 74PG96 0 13 20 0 24 43 PG97 10 26 33 14 47 61 PG98 16 20 0 47 54 0 PG99 190 26 41 0 54 PG100 20 21 24 39 57 41 PG102 27 20 31 50 61 61 PG104 16 2326 46 44 49

TABLE 5 Percentage identity and percentage similarity of variousproteins with the TonBIII box of P. gingivalis. Protein name Percentidentity Percent similarity PG2 46 71 PG13 57 93Cloning, Expression and Purification of Recombinant P. gingivalis Genes.

PG1

Oligonucleotides to the 5′ and 3′ regions of the deduced protein wereused to amplify the gene of interest from a preparation of P. gingivalisW50 genomic DNA using the TaqPlus Precision PCR System (Stratagene) anda PTC-100 (MJ Research) thermal cycler or similar device. The 5′oligonucleotide primer sequence was GCGCCATATGCTGGCCGAACCGGCC (SEQ IDNO: 149) the 3′ oligonucleotide primer sequence wasGCGCCTCGAGTCAATTCATTTCCTTATAGAG (SEQ ID NO: 150). The PCR fragment waspurified, digested with Nde I, Xho I restriction enzymes (Promega) andligated into the corresponding sites of the plasmid pProEx-1 (Gibco-BRL)and transformed into E. coli ER1793 cells (a gift from ElizabethRaleigh, New England Biolabs). A resulting clone expressing the correctinsert was selected and induced with or without 0.1 mM IPTG (Promega)for expression of the recombinant protein. Expression of the recombinantprotein was determined by SDS-PAGE analysis and Western Blot using theone of the rabbit antisera described above or an anti-hexahistidineantibody (Clontech) that detects the hexahistidine tag that was fused tothe P. gingivalis recombinant protein. PG1 was purified by disruption ofthe E. coli cells by sonication in binding buffer (Novagen) andsolubilisation by the addition of sarkosyl (N-Lauroyl sarcosine) to a 1%final concentration. There after the preparation was diluted to 0.1%sarkosyl in binding buffer, bound to a Nickel-nitrilotriacetic acidcolumn (Ni-NTA; Qiagen), after washing bound proteins were eluted with1M imidazole in elution buffer (Novagen) according to the Qiagenrecommendations with 0.1% sarkosyl added to all buffers. Followingpurification samples were dialysed against 500 mM NaCl, 20 mM Tris, 0.1%sarkosyl at pH7.4 to remove the imidazole, concentrated as required andstored at 4° C. until used. Purity and antigenicity were assessed bySDS-PAGE and Western blot using selected antisera (from those describedabove) and the protein concentration was determined by the BCA assay(Pierce).

PG2

The methods used for PG2 were essentially the same as for PG1 with thefollowing exceptions. The 5′ oligonucleotide primer sequence wasCGCGGTATACATGAAAAGAATGACGC (SEQ ID NO: 151), the 3′ oligonucleotideprimer sequence was CGCGAGATCTGAAAGACAACTGAATACC (SEQ ID NO: 152) andthe PCR product was cloned into pGex-stop RBS(IV) (Patent applicationWO9619496, J C Cox, S E Edwards, I Frazer and E A Webb. Variants ofhuman papilloma virus antigens) using the BstZ 171 and Bgl IIrestriction sites. 2% sarkosyl was used to solubilise PG2 and 8M ureawas added to the solublisation buffer and to all other buffers. Urea wasremoved from the purified protein by sequential dialysis (4M then 2Mthen 1M then 0.5M then 0M urea all in 50 mM Tris, 500 mM NaCl, 0.1%sarkosyl, pH7.4). Purified protein was stored at 4° C. until required.

PG3

The methods used for PG3 were essentially the same as for PG1 with thefollowing exceptions. The 5′ oligonucleotide primer sequence wasGCGCGTATACATGAAGAAATCAAGTGTAG (SEQ ID NO: 153), the 3′ oligonucleotideprimer sequence was GCGCAGATCTCTTCAGCGTACCTTGCTGTG (SEQ ID NO: 154) andDNA was amplified with Pfu DNA polymerase (Stratagene). The PCR productwas cloned directly into pCR-Blunt and transformed into E. coli Top 10F′(InVitrogen) before subcloning into the expression plasmid pGex-stopRBS(IV) using the Bst Z171 and Bgl II restriction sites and transformedinto E. coli BL21DE3 (Pharmacia Biotech). The following modificationswere made to the purification of PG3 from the PG1 method. Cellsexpressing the recombinant protein were disrupted by sonication inbinding buffer and the insoluble inclusion bodies concentrated bycentrifugation. Inclusion bodies were then solubilised in 6M urea(Sigma) in binding buffer and eluted with 6M urea added to the elutionbuffer. In some instances 6M guanidine hydrochloride (Sigma) was usedinstead of urea for these steps. Urea (or guanidine hydrochloride whenit was substituted) was removed from the purified protein by sequentialdialysis against reducing levels of urea (3M then 1.5M then 0.5M then 0Murea all in 50 mM Tris, 500 mM NaCl, 8% glycerol, pH7.4). Purifiedprotein was stored frozen at −80° C. until required. Proteinconcentration was determined by the Coomassie Plus protein assay(Pierce).

PG4

The methods used for PG4 were essentially the same as for PG3 with thefollowing exceptions. The 5′ oligonucleotide primer sequence wasCTTCTGTATACTTACAGCGGACATCATAAAATC (SEQ ID NO:155), the 3′oligonucleotide primer sequence was TTCCAGGAGGGTACCACGCAACTCTTCTTCGAT(SEQ ID NO: 156) and DNA was amplified with the Tth XL PCR kit (PerkinElmer). The PCR product was cloned into the expression plasmid pGex-stopRBS(IV) using the Bst Z171 and Kpn I restriction sites and transformedinto E. coli ER1793.

PG5

The methods used for PG5 were essentially the same as for PG3 with thefollowing exceptions. The 5′ oligonucleotide primer sequence wasTTGCAACATATGATCAGAACGATACTTTCA (SEQ ID NO: 157) the 3′ oligonucleotideprimer sequence was AGCAATCTCGAGCGGTTCATGAGCCAAAGC (SEQ ID NO: 158) andDNA was amplified with the Tth XL PCR kit. The PCR product was clonedinto the expression plasmid pET24 (Novagen) using the Nde I and Xho Irestriction sites and transformed into E. coli BL21 (Pharmacia Biotech).Removal of urea was not proceeded past 1M urea as the protein wasinsoluble at lower concentrations of urea. Purified protein was storedat 4° C. until required.

PG6

The methods used for PG6 were essentially the same as for PG3 with thefollowing exceptions. The 5′ oligonucleotide primer sequence wasTAAACATATGTCCCTCGAACCCATAATTGCTCCG (SEQ ID NO:159), the 3′oligonucleotide primer sequence was CGTCCGCGGAAGCTTTGATCGGCCATTGCTACT(SEQ ID NO: 160) and DNA was amplified with the Tth XL PCR kit. The PCRproduct was cloned into the expression plasmid pET24a using the Nde Iand Hind III restriction sites and transformed into E. coli BL21.

PG8

The methods used for PG8 were essentially the same as for PG3 with thefollowing exceptions. The 5′ oligonucleotide primer sequence wasCGCGGTATACATGGAGTTCAAGATTGTG (SEQ ID NO:161), the 3′ oligonucleotideprimer sequence was CGCGAGATCTGTTTTCTGAAAGCTTTTC (SEQ ID NO: 162) andDNA was amplified with the TaqPlus Precision PCR System. The PCR productwas cloned into the expression plasmid pProEx-1 using the Nde I and XhoI restriction sites and transformed into E. coli ER1793.

PG8A

PG8A is a shortened version of PG8 and has the first 173 amino acidsremoved. The methods used for PG8A were essentially the same as for PG3with the following exceptions. The 5′ oligonucleotide primer sequencewas CGCGGTATACATGGAAAACTTAAAGAAC (SEQ ID NO:163), the 3′ oligonucleotideprimer sequence was CGCGAGATCTGTTTTCTGAAAGCTTTTC (SEQ ID NO: 164) andDNA was amplified with the TaqPlus Precision PCR System. The PCR productwas cloned into the expression plasmid pGex-stop RBS(IV) using the BstZ171 and Bgl II restriction sites and transformed into E. coli ER1793.Prior to dialysis of the purified protein EDTA (Sigma) was added to afinal concentration of 10 mM.

PG10

The methods used for PG10 were essentially the same as for PG3 with thefollowing exceptions. The 5′ oligonucleotide primer sequence wasCGCGGATATCATGGATAAAGTGAGCTATGC (SEQ ID NO:165), the 3′ oligonucleotideprimer sequence was CGCGAGATCTTTTGTTGATACTCAATAATTC (SEQ ID NO: 166) andDNA was amplified with the TaqPlus Precision PCR System. The PCR productwas digested with Eco RV and Bgl II and ligated into the expressionplasmid pGex-stop RBS(IV) using the Bst Z171 and Bgl II restrictionsites and transformed into E. coli ER1793.

PG11

The methods used for PG11 were essentially the same as for PG1 with thefollowing exceptions. The 5′ oligonucleotide primer sequence wasGCGCGTATACATGAGAGCAAACATTTGGCAGATACTTTCCG (SEQ ID NO: 167), the 3′oligonucleotide primer sequence was GCGCAGATCTGCGCAAGCGCAGTATATCGCC (SEQID NO: 168) and DNA was amplified with Tli DNA polymerase (Promega). ThePCR product was cloned into pCR-Blunt and transformed into E. coliTop10F′ before subcloning into the expression plasmid pGex-stop RBS(IV)using the Bst Z171 and Bgl II restriction sites and transformed into E.coli ER1793. PG11 was purified by solubilisation of E. coli cells with2% sarkosyl in binding buffer (Qiagen) which was diluted to 0.1%sarkosyl in binding buffer, bound to a Nickel-nitrilotriacetic acidcolumn (Ni-NTA; Qiagen), after washing bound proteins were eluted with1M imidazole (0.7% CHAPS (Sigma) in elution buffer; Qiagen) according tothe Qiagen recommendations. Following purification samples were dialysedagainst 500 mM NaCl, 20 mM Tris, 0.7% CHAPS, 20% glycerol (Sigma) atpH7.4 to remove the imidazole, concentrated as required and stored at 4°C. until used.

PG12

The methods used for PG12 were essentially the same as for PG1 with thefollowing exceptions. The 5′ oligonucleotide primer sequence wasGCGCGTATACATGAATAGCAGACATCTGACAATCACAATCATTGCCGG (SEQ ID NO: 169), the3′ oligonucleotide primer sequence wasGCGCAGATCTGCTGTTCTGTGAGTGCAGTTGTTTAAGTG (SEQ ID NO: 170) and DNA wasamplified with Tli DNA polymerase. The PCR product was cloned intopCR-Blunt and transformed into E. coli Top10F′ cells before subcloninginto the expression plasmid pGex-stop RBS(IV) using the Bst Z171 and BglII restriction sites and transformed into E. coli BL21. Purification ofthe recombinant protein was essentially the same as PG11 except 0.5%DHPC (1,2-Diheptanoyl-sn-glycero-3-phosphocholine; Avanti) in 50 mMTris, 50 mM NaCl, pH8.0 was used to solubilise the inclusion bodiesinstead of sarkosyl and the DHPC was diluted to 0.1% before addition tothe Ni-NTA and 0.1% DHPC was added to all buffers.

PG13

The methods used for PG13 were essentially the same as for PG3 with thefollowing exceptions. The 5′ oligonucleotide primer sequence wasGCGCCATATGCGGACAAAAACTATCTTTTTTGCG (SEQ ID NO:171), the 3′oligonucleotide primer sequence wasGCGCCTCGAGGTTGTTGAATCGAATCGCTATTTGAGC (SEQ ID NO: 172) and DNA wasamplified with Tli DNA polymerase. The PCR product was cloned theexpression plasmid pET24b using the Nde I and Xho I restriction sitesand transformed into E. coli BL21. Purification of the recombinantprotein was essentially the same as PG3 using 6M urea and 1% NOG(n-octyl glucoside; Sigma) was added to the dialysis buffer. Removal ofurea was not proceeded past 2M urea as the protein was insoluble atlower concentrations of urea. Purified protein was stored at 4° C. untilrequired.

PG14

The methods used for PG12 were essentially the same as for PG1 with thefollowing exceptions. The 5′ oligonucleotide primer sequence wasGCGCGGCGCCATGACGGACAACAAACAACGTAATATCG (SEQ ID NO: 173), the 3′oligonucleotide primer sequence wasGCGCCTCGAGTTACTTACGTATGATCACGGACATACCC (SEQ ID NO: 174) and DNA wasamplified with Tli DNA polymerase. The PCR product was cloned theexpression plasmid pProEx-1 using the Ehe I and Xho I restriction sitesand transformed into E. coli BL21. Purification of the recombinantprotein was essentially the same as PG12.

PG22

The methods used for PG22 were essentially the same as for PG1 with thefollowing exceptions. The 5′ oligonucleotide primer sequence wasCCCCGGATCCGATGCGACTGATCAAGGC (SEQ ID NO:175), the 3′ oligonucleotideprimer sequence was CCCCCTCGAGCGGAACGGGGTCATAGCC (SEQ ID NO: 176) andDNA was amplified with the TaqPlus Precision PCR System. The PCR productwas cloned into the expression plasmid pET24b using the Bam HI and Xho Irestriction sites and transformed into E. coli BL21DE3. Once PG22 waspurified dialysis was performed in the same manner as for PG1 but in thepresence of 1M imidazole.

PG24

The methods used for PG24 were essentially the same as for PG3 with thefollowing exceptions. The 5′ oligonucleotide primer sequence wasCGCGGTATACATGAATTACCTGTACATAC (SEQ ID NO: 177), the 3′ oligonucleotideprimer sequence was CGCGGGATCCGTTCGATTGGTCGTCGATGG (SEQ ID NO: 178) andDNA was amplified with the TaqPlus Precision PCR System. The PCR productwas digested with Bst Z171 and Bam HI and ligated into the expressionplasmid pGex-stop RBS(IV) using the Bst Z171 and Bgl II restrictionsites and transformed into E. coli ER1793. Due to the low level ofexpression of PG24 purification was not proceeded with except on smallscale.

PG24A

A modified version of PG24 was also cloned and expressed. PG24A is thesame as PG24 with the predicted N-terminal sequence removed. The methodsused for PG24A were essentially the same as for PG3 with the followingexceptions. The 5′ oligonucleotide primer sequence wasCGCGCATATGGAGATTGCTTTCCTTTCTTCG (SEQ ID NO: 179), the 3′ oligonucleotideprimer sequence was CGCGCTCGAGTTAGTTCGATTGGTCGTCG (SEQ ID NO: 180) andDNA was amplified with the TaqPlus Precision PCR System. The PCR productwas cloned into the expression plasmid pProEx-1 using the Nde I and XhoI restriction sites and transformed into E. coli ER1793. Purification ofthe recombinant protein was essentially the same as PG3 except 8M ureawas used to solubilise the inclusion bodies and in the buffers used forthe Ni-NTA column purification. Urea was removed by sequential dialysis(4M then 2M, then 1M then 0.5M then 0M urea all in 50 mM Tris, 500 mMNaCl, 8% glycerol, pH7.4). Purified protein was stored frozen at −80° C.until required.

PG29

The methods used for PG29 were essentially the same as for PG3 with thefollowing exceptions. The 5′ oligonucleotide primer sequence wasGCGCGATATCGCTAGCATGAAAAAGCTATTTCTC (SEQ ID NO: 181), the 3′oligonucleotide primer sequence wasGCGCAGATCTCTCGAGTTTGCCATCGGATTGCGGATTG (SEQ ID NO: 182) and DNA wasamplified with Pfu DNA polymerase being used. The PCR product was clonedinto pCR-Blunt (InVitrogen) and transformed into E. coli Top10F′ beforesubcloning into the expression plasmid pGex-stop RBS(IV) using the EcoRV and Bgl II restriction sites and transformed into E. coli BL21. 6Murea was used throughout the purification process.

PG54

The methods used for PG54 were essentially the same as for PG3 with thefollowing exceptions. The predicted N-terminal signal sequence wasremoved from the recombinant protein. The 5′ oligonucleotide primersequence was CGCTGAATTCCAGATTTCGTTCGGAGGGGAACCC (SEQ ID NO: 183), the 3′oligonucleotide primer sequence was CTATGCGGCCGCCTGCTTCACGATCTTTTGGCTCA(SEQ ID NO: 184) and DNA was amplified with the Tth XL PCR kit. The PCRproduct was cloned into the expression plasmid pET24a using the Eco RIand Not I restriction sites and transformed into E. coli BL21DE3.Expression studies and immunoreactivity studies were carried out onwhole E. coli lysates. Purification was not done for these studies.

PG57

The methods used for PG57 were essentially the same as for PG3 with thefollowing exceptions. The predicted N-terminal signal sequence wasremoved from the recombinant protein. The 5′ oligonucleotide primersequence was TGCTGGATCCCAAGAGATCTCAGGCATGAATGCA (SEQ ID NO: 185), the 3′oligonucleotide primer sequence wasGAGTGCGGCCGCTCGGCCTCTTTATCTCTACCTTTTC (SEQ ID NO: 186) and DNA wasamplified with the Tth XL PCR kit. The PCR product was cloned into theexpression plasmid pET24a using the Bam HI and Not I restriction sitesand transformed into E. coli BL21DE3. Expression studies andimmunoreactivity studies were carried out on whole E. coli lysates.Purification was not done for these studies.

PG68

The methods used for PG68 were essentially the same as for PG3 with thefollowing exceptions. The predicted N-terminal signal sequence wasremoved from the recombinant protein. The 5′ oligonucleotide primersequence was GCTTGCGGCCGCCCTTATGAAAGATTTGCAGAT (SEQ ID NO: 187), the 3′oligonucleotide primer sequence was GGTGCTCGAGTATACTCAACAAGCACCTTATGCAC(SEQ ID NO: 188) and DNA was amplified with the Tth XL PCR kit. The PCRproduct was cloned into the expression plasmid pET24a using the Not Iand Xho I restriction sites and transformed into E. coli BL21DE3.Expression studies and immunoreactivity studies were carried out onwhole E. coli lysates. Purification was not done for these studies.

PG75

The methods used for PG75 were essentially the same as for PG3 with thefollowing exceptions. The predicted N-terminal signal sequence wasremoved from the recombinant protein. The 5′ oligonucleotide primersequence was GGCGGGATCCGCTCAGGAGCAACTGAATGTGGTA (SEQ ID NO: 189), the 3′oligonucleotide primer sequence wasGAGTGCGGCCGCTGTGGAACAAATTGCGCAATCCATC (SEQ ID NO: 190) and DNA wasamplified with the Tth XL PCR kit. The PCR product was cloned into theexpression plasmid pET24a using the Bam HI and Not I restriction sitesand transformed into E. coli BL21DE3. Expression studies andimmunoreactivity studies were carried out on whole E. coli lysates.Purification was not done for these studies.

PG76

The methods used for PG76 were essentially the same as for PG3 with thefollowing exceptions. The predicted N-terminal signal sequence wasremoved from the recombinant protein. The 5′ oligonucleotide primersequence was AGCAGAATTCGGAAACGCACAGAGCTTTTGGGAA (SEQ ID NO: 191), the 3′oligonucleotide primer sequence wasGAGTGCGGCCGCTTACCTGCACCTTATGACTGAATAC (SEQ ID NO: 192) and DNA wasamplified with the Tth XL PCR kit. The PCR product was cloned into theexpression plasmid pET24a using the Eco RI and Not I restriction sitesand transformed into E. coli BL21DE3. Expression studies andimmunoreactivity studies were carried out on whole E. coli lysates.Purification was not done for these studies.

PG91

The methods used for PG91 were essentially the same as for PG3 with thefollowing exceptions. The predicted N-terminal signal sequence wasremoved from the recombinant protein. The 5′ oligonucleotide primersequence was TGCTGAATTCCAGACGATGGGAGGAGATGATGTC (SEQ ID NO: 193), the 3′oligonucleotide primer sequence wasGAGTGCGGCCGCTTTCCACGATGAGCTTCTCTACGAA (SEQ ID NO: 194) and DNA wasamplified with the Tth XL PCR kit. The PCR product was cloned into theexpression plasmid pET24a using the Eco RI and Not I restriction sitesand transformed into E. coli BL21DE3. Expression studies andimmunoreactivity studies were carried out on whole E. coli lysates.Purification was not done for these studies.

PG94

The methods used for PG94 were essentially the same as for PG3 with thefollowing exceptions. The predicted N-terminal signal sequence wasremoved from the recombinant protein. The 5′ oligonucleotide primersequence was GGCCGAGCTCCAAGAGGAAGGTATTTGGAATACC (SEQ ID NO: 195), the 3′oligonucleotide primer sequence wasGAGTGCGGCCGCTTTGTCCTACCACGATCATTTTCTT (SEQ ID NO: 196) and DNA wasamplified with the Tth XL PCR kit. The PCR product was cloned into theexpression plasmid pET24a using the Eco RI and Not I restriction sitesand transformed into E. coli BL21DE3. Expression studies andimmunoreactivity studies were carried out on whole E. coli lysates.Purification was not done for these studies.

PG96

The methods used for PG96 were essentially the same as for PG3 with thefollowing exceptions. The predicted N-terminal signal sequence wasremoved from the recombinant protein. The 5′ oligonucleotide primersequence was TGCTGAGCTCCAAACGCAAATGCAAGCAGACCGA (SEQ ID NO: 197), the 3′oligonucleotide primer sequence wasGAGTGCGGCCGCTTTTGAGAATTTTCATTGTCTCACG (SEQ ID NO: 198) and DNA wasamplified with the Tth XL PCR kit. The PCR product was cloned into theexpression plasmid pET24a using the Sac I and Not I restriction sitesand transformed into E. coli BL21DE3. Expression studies andimmunoreactivity studies were carried out on whole E. coli lysates.Purification was not done for these studies.

PG97

The methods used for PG97 were essentially the same as for PG3 with thefollowing exceptions. The predicted N-terminal signal sequence wasremoved from the recombinant protein. The 5′ oligonucleotide primersequence was GGCGGGATCCCAGTTTGTTCCGGCTCCCACCACA (SEQ ID NO: 199), the 3′oligonucleotide primer sequence wasGAGTGCGGCCGCTCTGTTTGATGAGCTTAGTGGTATA (SEQ ID NO: 200) and DNA wasamplified with the Tth XL PCR kit. The PCR product was cloned into theexpression plasmid pET24a using the Bam HI and Not I restriction sitesand transformed into E. coli BL21DE3. Expression studies andimmunoreactivity studies were carried out on whole E. coli lysates.Purification was not done for these studies.

PG98

The methods used for PG98 were essentially the same as for PG3 with thefollowing exceptions. The predicted N-terminal signal sequence wasremoved from the recombinant protein. The 5′ oligonucleotide primersequence was AGCAGAATTCCAAGAAAGAGTCGATGAAAAAGTA (SEQ ID NO: 201), the 3′oligonucleotide primer sequence wasGAGTGCGGCCGCTTAGCTGTGTAACATTAAGTTTTTTATTGAT (SEQ ID NO: 202) and DNA wasamplified with the Tth XL PCR kit. The PCR product was cloned into theexpression plasmid pET24a using the Eco RI and Not I restriction sitesand transformed into E. coli BL21DE3. Expression studies andimmunoreactivity studies were carried out on whole E. coli lysates.Purification was not done for these studies.

PG99

The methods used for PG99 were essentially the same as for PG3 with thefollowing exceptions. The predicted N-terminal signal sequence wasremoved from the recombinant protein. The 5′ oligonucleotide primersequence was TGCTGAATTCAAGGACAATTCTTCTTACAAACCT (SEQ ID NO: 203), the 3′oligonucleotide primer sequence wasGAGTGCGGCCGCTTCGAATCACGACTTTTCTCACAAA (SEQ ID NO: 204) and DNA wasamplified with the Tth XL PCR kit. The PCR product was cloned into theexpression plasmid pET24a using the Eco RI and Not I restriction sitesand transformed into E. coli BL21DE3. Expression studies andimmunoreactivity studies were carried out on whole E. coli lysates.Purification was not done for these studies.

PG100

The methods used for PG100 were essentially the same as for PG3 with thefollowing exceptions. The predicted N-terminal signal sequence wasremoved from the recombinant protein. The 5′ oligonucleotide primersequence was GGCAGAATTCCAGTCTTTGAGCACAATCAAAGTA (SEQ ID NO: 205), the 3′oligonucleotide primer sequence wasGAGTGCGGCCGCTGATAGCCAGCTTGATGCTCTTAGC (SEQ ID NO: 206) and DNA wasamplified with the Tth XL PCR kit. The PCR product was cloned into theexpression plasmid pET24a using the Eco RI and Not I restriction sitesand transformed into E. coli BL21DE3. Expression studies andimmunoreactivity studies were carried out on whole E. coli lysates.Purification was not done for these studies.

PG102

The methods used for PG102 were essentially the same as for PG3 with thefollowing exceptions. The predicted N-terminal signal sequence wasremoved from the recombinant protein. The 5′ oligonucleotide primersequence was GGCCGAATTCCAGATGGATATTGGTGGAGACGAT (SEQ ID NO: 207), the 3′oligonucleotide primer sequence wasGAGTGCGGCCGCTCTCTACAATGATTTTTTCCACGAA (SEQ ID NO: 208) and DNA wasamplified with the Tth XL PCR kit. The PCR product was cloned into theexpression plasmid pET24a using the Eco RI and Not I restriction sitesand transformed into E. coli BL21DE3. Expression studies andimmunoreactivity studies were carried out on whole E. coli lysates.Purification was not done for these studies.

PG104

The methods used for PG104 were essentially the same as for PG3 with thefollowing exceptions. The predicted N-terminal signal sequence wasremoved from the recombinant protein. The 5′ oligonucleotide primersequence was GAACGGATCCAACGTGTCTGCTCAGTCACCCCGA (SEQ ID NO: 209), the 3′oligonucleotide primer sequence wasGAGTGCGGCCGCTTCTGAGCGATACTTTTGCACGTAT (SEQ ID NO: 210) and DNA wasamplified with the Tth XL PCR kit. The PCR product was cloned into theexpression plasmid pET24a using the Bam HI and Not I restriction sitesand transformed into E. coli BL21DE3. Expression studies andimmunoreactivity studies were carried out on whole E. coli lysates.Purification was not done for these studies.

Animal Antisera and Human Patient Sera.

Various antisera were raised for detecting the expression and refoldingof the recombinant P. gingivalis proteins. A whole cell antisera wasraised by injecting New Zealand White rabbits with 3 doses of sonicatedP. gingivalis (strain W50) containing approximately 2 mg of protein. Thefirst dose was given in Freunds complete adjuvant (FCA) and the secondand third doses were given in Freunds incomplete adjuvant (IFA) at 3week intervals. Doses (1 ml) were given intramuscularly into the hindlegs and rabbits bled 7 days after the last dose, the blood clotted andserum removed and stored at −20° C. until required. A second rabbitantisera was produced in a similar manner but using a sarkosyl insolublefraction (each dose was 0.69 mg of protein) derived from P. gingivalisW50 according to the method of Doidg and Trust T. et al 1994 as theimmunogen. A third rabbit antisera was produced in a similar manner tothe first only the sarkosyl soluble fraction (1 mg of protein per dose)derived from P. gingivalis W50 cells according to the method of Doidg P.and Trust T J. (1994 Infect Immun 62:4526-33) was used as the immunogen.

A “protected rat serum” pool was also used in these studies and wasobtained from rats immunised with formalin killed whole P. gingivaliscells in FIA (strain ATCC 33277; 2 doses of 2×10⁹ cells, 3 weeks apart).Rats were then challenged 2 weeks after their last dose with live P.gingivalis cells (strain 33277) given orally as previously described(Klaussen B. et al. 1991, Oral Microbiol Immunol 6:193-201) and theserum obtained from these rats 6 weeks after the final challengeinoculation at the time of sacrifice.

Human sera were obtained from adult patients undergoing treatment orassessment for periodontitis at an outpatient clinic. These patients hadat least 6 teeth with 6 mm attachment loss and had P. gingivalis presentin their sub-gingival plaque as detected using a P. gingivalis specificDNA probe. Sera was pooled from these patients and compared to a pool ofsera from periodontally healthy patients.

Immunization and Murine Lesion Model Protocols

The mouse abscess model was used to assess the efficacy of immunisingmice with recombinant P. gingivalis proteins in protecting mice fromformation of a subcutaneous abscess. This model has been used by othersas a predictor of potential vaccines against periodontal disease (Bird PS, et al. 1995 J. Periodontal. 66:351-362. BALB/c mice 6-8 weeks oldwere immunised by subcutaneously injecting them with 0.1 ml containingeither 10 or 20 μg of recombinant P. gingivalis protein, 20 μg of E.coli lysate protein, 2×10⁹ formalin killed cells of P. gingivalis strain33277 emulsified in incomplete Freund's adjuvant (WA; Sigma) on day 0.At day 21 mice were re-injected with the same dose and then bled 1 weeklater and evaluated for antibody levels. At day 35 mice all mice werechallenged with approximately 2×10⁹ cells of live P. gingivalis (ATCC33277) by subcutaneous injection in the abdomen. Following challengemice were monitored daily for weight loss and the size of the lesionmeasured for the next 10 days. Lesion sizes were measured by length andwidth and expressed as mm². Groups were statistically analysed using aKruskal-Wallis one-way ANOVA and were also individually examined usingthe unpaired t test or Mann-Whitney rank sum test using the Instatstatistical package.

FIG. 1 shows the results of one experiment at day 4 after challenge(lesions were at maximum size at this time point). Control miceimmunised with E. coli lysate showed large lesions while mice immunisedwith killed cells of P. gingivalis strain 33277 were fully protected.This indicates that whole cells provide protection against P. gingivaliswhile E. coli protein immunised mice were not protected. Mice given thevarious PG recombinant proteins showed significant levels of protectionfor PG2, PG22, PG24 and PG29 (p<0.05 unpaired t test) while PG8A was notquite significantly different (p=0.07) compared to the E. coli controlgroup.

FIG. 2 shows the results of a separate experiment using combinations ofrecombinant proteins. Mice given PG1+PG2 showed a significant level ofprotection compared to control mice give E. coli lysate (p<0.026unpaired t test).

IMMUNOSCREENING

Cloned candidates were cultured in 15 ml of Terrific broth, induced withIPTG and sampled at 4 h post-induction. One ml of culture was removed,pelleted and the cells resuspended in a volume of PBS determined bydividing the OD A_(600 nm) of the culture by 8. An aliquot of lysate(100 μl) was added to 100 μl of 2× sample reducing buffer (125 mM TrispH 6.8, 20% glycerol, 4% SDS, 80 mM DTT, 0.03% bromophenol blue) andboiled for 10 min. SDS-PAGE was performed according to the method ofLaemmli UK. 1970 (Nature 227:680-685) using 4-20% 1.0 mm Tris-Glycinegels (Novex) according to the manufacturers recommendations. Proteinswere transferred onto Hybond-C Extra nitrocellulose membranes (Amersham)by transblotting and the membranes were then blocked for 2 h at roomtemperature (RT) in 5% skim milk in 20 mM Tris, 0.5M NaCl, 0.05%Tween-20, pH 7.5 (TTBS). Immunoscreening was performed separately withthe rabbit anti-P. gingivalis whole cell serum, the rat protectiveserum, a pool of human periodontal patients serum, and in many cases ananti-T7-Tag antibody HRP conjugate (Novagen). Prior to use, the rabbit,rat and human sera were diluted 1/5000, 1/1000 and 1/500 respectively in5% skim milk in TTBS and absorbed with 100 μl (for the rabbit serum) or250 μl (for the rat and human sera) E. coli extract (20 mg/ml; Promega)for 6 h at RT.

Membranes were incubated overnight at RT with the absorbed antisera, orfor 1 hr at RT with 1/5000 diluted anti-T7-Tag conjugate. Following 3×10min washes with TTBS, HRP-conjugated anti-rabbit (Silenus), anti-mouse(Silenus) or anti-human (KPL) antibody, diluted 1/5000 in 5% skim milkin TTBS, was added for 1 h at RT. Membranes were washed as before, priorto addition of TMB membrane peroxidase substrate (KPL) for detection ofimmunoreactive proteins. Results of reactivity for the recombinant P.gingivalis proteins is shown in Table 7.

In addition some of the sera (pooled sera diluted 1/1000) from the miceimmunised with P. gingivalis recombinant proteins (prior to challenge)were analysed for their reactivity against Western blots of whole nativeW50 P. gingivalis proteins using similar techniques as those outlinedabove. PG2, PG8A, PG29 and PG3 all showed bands at a similar molecularweight to that of the recombinant PG protein in the native W50 blot.This indicates that PG proteins are expressed in the W50 strain and thatthe recombinant proteins have at least some identical immunogenicity tothe native proteins.

m-RNA Analysis

Hot Phenol RNA Extraction

P. gingivalis W50 cells (150 ml culture) were grown anaerobically to midlog phase (OD A₆₀₀=0.18) mixed with 50% glycerol and stored at −70° C.until RNA extraction. Cells were pelleted by centrifugation at 6000 g,and resuspended in 8 ml ASE (20 mM NaOAc, 0.5% SDS, 1 mM EDTA). An equalvolume of 20 mM NaOAc(pH 4.5)-saturated phenol was added and mixed byshaking for 30 seconds, incubated at 65° C. for 5 minutes, followed by afurther 5 second shaking and repeated incubation. After cooling, 2 mlchloroform was added and mixed by shaking for 5 seconds, and the mixturespun at 10000 g for 10 minutes at 4° C. The top aqueous phase wastransferred and re-extracted by repeating the phenol and chloroformsteps. The aqueous phase was transferred again and 100U RNase inhibitor(RNAsin; Promega) were added. RNA was precipitated with 3 volumes 100%ethanol at −20° C. overnight. The RNA precipitate was recovered bycentrifugation at 10000 g at 4° C. for 15 minutes, then washed with 100%ethanol, dried and resuspended in 600 μl sterile, deionised, dH₂O with 1μl of fresh RNase inhibitor. RNA was aliquoted and stored at −70° C. TheRNA concentration was determined spectrophotometrically. A formaldehydeRNA gel confirmed RNA integrity (Sambrook J. et al. 1989, MolecularCloning. A laboratory manual. Cold Spring Laboratory Press, New York.2nd Edition).

RT-PCR

The isolated RNA was used as a template for Reverse Transcription (RT)to produce cDNA. Varying RNA concentrations were used for the RT as eachRNA transcript was potentially present at different levels. Subsequentamplification of the cDNA was performed using Polymerase Chain Reaction(PCR). RT-PCR was performed using GeneAmp® RNA PCR Kit (Perkin Elmer)according to the manufacturer's protocol with the following exception tothe PCR; 35 cycles were performed as follows: Melt phase 95° C. for 30seconds, Anneal phase varied between 50-60° C. for 30 seconds, Extensionphase 72° C. for 1 minute. Amplification was performed in a PTC-100Programable Thermal Controller (MJ Research Inc.). As a control todemonstrate that the amplified product did not arise from contaminatingDNA, Reverse Transcriptase (RTase) was omitted from a parallel tube. ThePCR products were examined against DNA markers (GIBCO 1 kB ladder) on a1% agarose gel stained with ethidium bromide.

RT-PCR results are shown in Table 6 using the oligonucleotide primers asused in “Cloning, expression and purification of recombinant P.gingivalis genes” section described above, except for the followingchanges. For PG1 the 3′ reverse primer used wasGCGCCTCGAGATTCATTTCCTTATAGAG (SEQ ID NO: 211), for PG4 the 5′ forwardprimer was CTTCTTGTCGACTACAGCGGACATCATAAAATC (SEQ ID NO: 212) and the 3′reverse primer was TTCCACCTCGAGTTAACGCAACTCTTCTTCGAT (SEQ ID NO: 213),for PG6 the 5′ forward primer was TAAAGAATTCTGCCTCGAACCCATAATTGCTCCG(SEQ ID NO: 214), for PG10 the 5′ forward primer wasCGCGCATATGGATAAAGTGAGCTATGC (SEQ ID NO: 215) and the 3′ reverse primerwas CGCGCTCGAGTTTGTTGATACTCAATAATTC (SEQ ID NO: 216), for PG13 the 5′forward primer was GCCCGGCGCCATGCGGACAAAAACTATCTTTTTTGCG (SEQ ID NO:217) and the 3′ reverse primer wasGCCCGGCGCCTTAGTTGTTGAATCGAATCGCTATTTGAGC (SEQ ID NO: 218). Amplificationof P. gingivalis transcripts is a likely indication that RNA for aspecific candidate is present and that the protein is produced. However,where there is no amplification achieved this does not indicate thatthis gene is never transcribed and may be the result of the cultureconditions or the state of the cells when harvested.

TABLE 6 Expression of PG m-RNA with in vitro grown P. gingivalis W50. \Approx. Expected RNA Annealing PCR fragment fragment PG # μg temp. ° C.RT-PCR (−RT) size bp size bp  1 0.15 55 + − 1300 1362  2 1.0 50 + − 32003051  3 0.15 60 + − 720 690  4 2.9 55 − − N.D. 2000  5 0.02 50 + − 1000947  6 1.0 55 + − 1000 972  8A 0.15 50 + − 1200 1278 10 0.15 55 + − 590585 11 0.10 60 + − 960 942 12 0.02 60 + − 880 831 13 1.0 50 + − 21502274 14 0.15 60 + − 1050 996 22 1.0 60 − − N.D. 228 24 1.0 55 + + 11501194 29 0.15 60 + − 880 885 The symbols are + band visible on agarosegel, − no band present on agarose gel, ND not detected.

TABLE 7 Immunoblot results of proteins expressed in E. coli againstrabbit, rat and human antisera. Deduced MW was calculated from aminoacid sequence of the P. gingivalis proteins, some of which had theirN-terminal signal sequences removed. Apparent MW was determined fromSDS-PAGE gels. The N- and C-terminal tags add approximately 2.5 KDa tothe deduced MW of the recombinant proteins. Protein Deduced MW ApparentAntisera reactivity number (KDa) MW (KDa) T7 Rabbit Rat Human PG1 47.563 ND − − − PG2 112.4 125.7 ND + − − PG3 22.6 18.3 ND −^(a) − − PG4 7590.6 ND − − − PG5 34.9 43.8 ND − − − PG6 36.7 47.1 ND − − − PG8 67.563.1 ND −^(b) − − PG8A 47.7 90.6 ND − − − PG10 21.3 25.5 ND + − + PG1136.2 42.4 ND − − − PG12 30.7 30.6 ND − − − PG13 84.5 101 ND − − − PG1436 42.4 ND − + + PG22 8.6 11.1 ND − − − PG24A 47 63.1 ND − − − PG29 31.140.9 ND + + + PG54 101.4 46.7 + + − − PG57 100 134.5 + + + + PG68 133.330.7 + − + + PG75 40.7 46.7 + − − − PG76 48.1 55.6 + − − + PG91 57.285.7 + + + + PG96 59.3 70.3 + + + + PG97 44.4 57.5 + − + + PG98 33.336 + − − − PG99 40.7 55.6 + − + + PG100 29.6 10.8 + − − − PG102 59.370.3 + − − + PG104 40.7 57.5 + − − + The symbols are + positive, −negative, +/− weak positive, ND not done. ^(a)Positive reaction detectedwith the rabbit antiserum to sarkosyl insoluble P. gingivalis antigen.^(b)Purified protein demonstrated weak positive reaction with the rabbitantiserum to whole P. gingivalis.

It will be appreciated by persons skilled in the art that numerousvariations and/or modifications may be made to the invention as shown inthe specific embodiments without departing from the spirit or scope ofthe invention as broadly described. The present embodiments are,therefore, to be considered in all respects as illustrative and notrestrictive.

REFERENCES

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1.-4. (canceled)
 5. An isolated antigenic Porphyromonas gingivalispolypeptide or an antigenic fragment thereof, the polypeptide comprisingan amino acid sequence selected from the group consisting of: SEQ. ID.NO. 110; SEQ. ID. NO. 111; SEQ. ID. NO. 112; SEQ. ID. NO. 113; SEQ IDNO: 120; SEQ. ID. NO. 123; SEQ. ID. NO. 124; SEQ. ID. NO. 125; SEQ. ID.NO. 130; SEQ. ID. NO. 131; SEQ. ID. NO. 132; SEQ. ID. NO. 133; SEQ. ID.NO. 135; SEQ. ID. NO. 136; SEQ. ID. NO. 137; SEQ. ID. NO. 138; SEQ. ID.NO. 143; SEQ. ID. NO. 144; SEQ. ID. NO. 145; SEQ. ID. NO. 146; SEQ. ID.NO. 147; and SEQ. ID. NO. 148; or amino acid sequences at least 95%identical to an amino acid sequence selected from the group consistingof: SEQ. ID. NO. 110; SEQ. ID. NO. 111; SEQ. ID. NO. 112; SEQ. ID. NO.113; SEQ ID NO: 120; SEQ. ID. NO. 123; SEQ. ID. NO. 124; SEQ. ID. NO.125; SEQ. ID. NO. 130; SEQ. ID. NO. 131; SEQ. ID. NO. 132; SEQ. ID. NO.133; SEQ. ID. NO. 135; SEQ. ID. NO. 136; SEQ. ID. NO. 137; SEQ. ID. NO.138; SEQ. ID. NO. 143; SEQ. ID. NO. 144; SEQ. ID. NO. 145; SEQ. ID. NO.146; SEQ. ID. NO. 147; and SEQ. ID. NO. 148; or an amino acid sequenceof at least 40 amino acids having a contiguous sequence of at least 40amino acids identical to a contiguous amino acid sequence selected fromthe group consisting of: SEQ. ID. NO. 110; SEQ. ID. NO. 111; SEQ. ID NO.112; SEQ. ID. NO. 113; SEQ ID NO: 120; SEQ. ID. NO. 123; SEQ. ID. NO.124; SEQ. ID. NO. 125; SEQ. ID. NO. 130; SEQ. ID. NO. 131; SEQ. ID. NO.132; SEQ. ID. NO. 133; SEQ. ID. NO. 135; SEQ. ID. NO. 136; SEQ. ID. NO.137; SEQ. ID. NO. 138; SEQ. ID. NO. 143; SEQ. ID. NO. 144; SEQ. ID. NO.145; SEQ. ID. NO. 146; SEQ. ID. NO. 147; and SEQ. ID. NO.
 148. 6. Apolypeptide or fragment thereof, the polypeptide comprising an aminoacid sequence selected from the group consisting of: SEQ. ID. NO. 110;SEQ. ID. NO. 111; SEQ. ID. NO. 112; SEQ. ID. NO. 113; SEQ ID NO: 120;SEQ. ID. NO. 123; SEQ. ID. NO. 124; SEQ. ID. NO. 125; SEQ. ID. NO. 130;SEQ. ID. NO. 131; SEQ. ID. NO. 132; SEQ. ID. NO. 133; SEQ. ID. NO. 135;SEQ. ID. NO. 136; SEQ. ID. NO. 137; SEQ. ID. NO. 138; SEQ. ID. NO. 143;SEQ. ID. NO. 144; SEQ. ID. NO. 145; SEQ. ID. NO. 146; SEQ. ID. NO. 147;and SEQ. ID. NO.
 148. 7. A composition for use in raising an immuneresponse directed against P. gingivalis in a subject, the compositioncomprising an effective amount of the polypeptide or fragment thereof asclaimed in claim 5 and a pharmaceutically acceptable carrier.
 8. Acomposition as claimed in claim 7 in which the pharmaceuticallyacceptable carrier comprises an adjuvant.